Webster's Revised Unabridged Dictionary · 1913

Gradatory

Gradatory , adjective

[See Grade.]

1.
Proceeding step by step, or by gradations; gradual.
Could we have seen [Macbeth's] crimes darkening on their progress... could this gradatory apostasy have been shown us. — A. Seward
2.
(Zoology) Suitable for walking; -- said of the limbs of an animal when adapted for walking on land.

Gradatory , noun

[Compare Late Latin gradatarium.]

(Architecture) A series of steps from a cloister into a church.